Enclosures will determine the appropriate envelope to be used, meaning the envelope will be one of the right size and strength.
•The size should properly accommodate the insert(s). Excessively large envelopes will not keep the inserts firm. The inserts in such envelopes slide about, create an imbalance of the envelope, risking ripping and loss of contents. A snug fit keeps the enclosure firm in the envelope providing for effective mail handling.
Conversely, when an envelope is overstuffed it can burst at the seams when machine processed. The result can be a total loss of the mailing.
•The strength of the envelope should be such to withstand the weight of its contents. If there is stress at the seams or sharp edges, the envelope is in an overload condition where it can burst or tear apart and lose its contents.